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Self-tapping screws with a press washer are self-screwing fasteners designed for reliable connection of solid products. These hardware are used for working with concrete, wood, metal, and for fixing sheet materials of different textures and densities. Examples of using self-tapping screws with a press washer:
- for the manufacture of structures from metal sheets and metal profiles;
- for connecting wooden slats, bars and other lumber;
- in construction for installation of drywall, sandwich panels, insulation, decorative materials to the base or to the frame;
- in instrument engineering, electrical engineering and radio engineering;
- production of furniture, interior items;
- installation of gypsum decorative elements on a wall made of concrete, brick, aerated concrete or other material.
Hardware is affordable, and there is a wide range of standard sizes for working with different materials. Self-tapping screws should be selected depending on the type of material and operating conditions of the hardware.
Features of self-tapping screws with drill
Self-tapping screws with drills are often used as fixing parts for metal structures. They make it more durable and as strong as possible. Thanks to them, the metal sheets are tightly fastened together.
During the manufacturing process, a special protective coating is applied to the screws. Because of this, the process of corrosion formation is prevented. Most often this is a galvanized version.
The quality requirements for these products are set out in GOST 11650-80.
The design of each such self-tapping screw has three main parts:
- Pointed tip;
- Full length thread;
- The cap is a support that prevents the part from going too deep into the material.
Table of size and weight of self-tapping screws with press washer
The dimensions and weight of self-tapping screws with a press washer, depending on the type of tip, are presented in the table:
| Size, designation | Weight, kg per 1000 pcs., sharp tip | Weight, kg per 1000 pcs., drill |
| SMM 4.2×13 | 1,4 | 1,75 |
| SMM 4.2×14 | 1,52 | 1,79 |
| SMM 4.2×16 | 1,6 | 1,94 |
| SMM 4.2×19 | 1,84 | 2,12 |
| SMM 4.2×25 | 2,23 | 2,50 |
| SMM 4.2×32 | 2,65 | 2,94 |
| SMM 4.2×41 | 3,25 | 3,6 |
| SMM 4.2×51 | 4,22 | 4,26 |
| SMM 4.2×76 | 5,16 | 5,68 |
What types are there?
With a press washer. High-quality self-tapping screws with a drill and a press washer are distinguished by a trapezoid-shaped head and a wide shoulder. Due to its volume, the cap presses the material quite tightly and firmly. The deep lug prevents the bat from slipping off. The diameter of this product is 4.2 mm.
There are two types of self-tapping screws with a drill:
- Pointed. Sheets of metal, 0.9 mm thick, are fastened together. No additional drilling required.
- Drill-tip. Can fasten sheets up to 5 mm thick. Excellent for interior installation work.
Cheaper options are usually used for domestic purposes. They differ in the flatness of the surface and the rounding of the head. A thin zinc coating does not protect the self-tapping screw from rust.
The shallow depth of the pin and the slipping of a screwdriver or bit can cause chips or scratches on the surface of the materials. In addition, among the cheap options there are often defects.
Description of self-tapping screws with press washer
Fine thread fasteners are versatile, durable and affordable. Other characteristic features of self-tapping screws with a press washer:
- hardware is protected from corrosion and has a long service life;
- fastening strength is ensured by fine threads and a press washer, which prevents spontaneous loosening of the hardware;
- Due to the wide shape of the cap, the material to which the self-tapping screw is attached is not pressed through.
Self-tapping screws are made of carbon and stainless steel, as well as brass. Carbon steel hardware is characterized by increased strength and is suitable for making highly loaded connections. Stainless steel fasteners are universal and resistant to precipitation, high humidity and vibration loads. Brass screws are considered the most wear-resistant. The color of the self-tapping screws with a press washer depends on the color of the galvanized protective coating (yellow or white). Galvanized fasteners do not spoil the appearance of the products being fastened and do not require additional painting.
The hardware installation process is extremely simple. There is no need to prepare a hole for installation; the procedure looks like this:
- mark the installation point of the self-tapping screw on the surface of the material;
- press the hardware to the marked point, pierce a hole (if the tip of the product is sharp enough and the base material gives way);
- Using a screwdriver or screwdriver, tighten the hardware.
Roofing screws with drill bit with EPDM gasket
This type is intended for outdoor work. These are fastening materials to metal structures, as well as to wooden sheathing.
Compressing the washer when screwing in leads to sealing of the recess. The head may have a paint coating to remain protected from corrosive processes. The washer is pressed against it during installation.
Roofing self-tapping screws - a drill with a pointed end - are necessary for securing the soft roof to the base. The reduced drill involves the use of corrugated sheeting to the surface of the wooden sheathing during installation work. An enlarged drill is used to firmly secure the decking to the metal base.
Varieties by area of use:
- For different types of wood and plastic. The difference from others is the rarity of the step in the carving. For a tree, they look like a trunk with very sparse carvings. The hat is easily hidden in the material without interfering with further work. A rare step is necessary to avoid the wood from crumbling.
Black parts are used to attach drywall and fasten wood elements together without additional drilling.
Models in yellow and white colors are suitable for fastening material with drilling. Do not rust, suitable for fittings.
- For sandwich panels. Fastening to metal occurs. Such elements are capable of independently drilling a sheet of metal with a thickness of 12-14 mm. Hex head, turnkey. The kit includes a washer along with a rubber gasket. This helps ensure the holes are waterproofed. The thickness of the materials varies from 1.5 to 12 mm.
- For drywall;
- For metal;
- For window profiles.
Types of carving
- Large. It runs along the entire trunk of the product, there is a rare step. Suitable for working with soft materials: wood, plaster, plastic.
- Average. Characteristic of universal self-tapping screws. They fix most materials.
- Asymmetrical. Typically applicable in the production process. In everyday life it is useful for assembling furniture.
- Notched variable. Acts as a fastening when working with brick or concrete surfaces, without using dowels.
Tips for choosing
Before you go shopping at a hardware store, you need to know a few rules for choosing.
- First, you need to accurately determine the material for which the screws are selected.
- Secondly, pay attention to the size of the parts.
- For materials with a small thickness, you should not purchase long and large-diameter models.
- They are more suitable for wood or thin metal sheets.
If you need to install a roof, choose only from roofing varieties. They can provide the required level of sealing of the holes.
Before purchasing, you must carefully inspect the screws. The surface must be smooth, without any curvature. You should not find even small irregularities on the thread. This can both ruin the material and cause a large amount of debris in the work process.
Products must be coated with special coatings. Protective coatings prevent corrosion. Most often these are galvanized or phosphated coatings. The tips can also be equipped with black sharp parts with a phosphated coating or with zinc plated ends in a light shade.
The advantages of working with such products
A self-tapping screw with a press washer, the price of which varies between 100-200 rubles per kilogram, has a number of undeniable advantages. The use of such devices makes it possible to avoid pre-drilling holes in the surface of the workpiece. This provides significant savings in time spent on installation and protects the material from destruction due to excessive exposure. In addition, connections made using these devices are characterized by increased reliability and durability. This is due to the fact that the self-tapping screw with the press washer is quite resistant to corrosion.
Thanks to the presence of a press washer, a tighter fit of the materials being joined is achieved, and the thread makes it possible to almost completely eliminate spontaneous unscrewing of the self-tapping screw due to shaking or vibration.
What affects quality
There are many factors that, to one degree or another, influence the quality of construction parts. However, the main ones are the following:
- The material from which the elements are made;
- Manufacturing technology and accuracy of its adherence.
In addition, it is better to purchase self-tapping screws, as well as other working materials, from trusted companies that have managed to establish themselves in the market. Now there is a big risk of falling for cheap, low-quality fakes.
It is usually better to opt for well-known brands and specialty stores. In addition to confidence in quality, you will receive professional advice from the staff.
Features of use
Equally important is knowledge about the correct use of self-tapping screws. The options used in the process of working with metal can withstand heavy loads.
To ensure their maximum service life, the elements must be screwed into the material in a certain step.
High-quality screws for metal have a sharp tip, so there is no need to drill additional holes for them.
However, if the sheet thickness is more than 2 mm, you will still need to prepare a recess, but of a smaller diameter than the self-tapping screw. This will make the screwing process easier.
What bit is needed for self-tapping screws with a press washer?
Hardware of this type has a head for a Phillips screwdriver. Cross holes are divided into two types: for a regular cross you need a Ph bit, for a cross with characteristic notches between the edges at 45 degrees you need a Pz type bit. The Ph bit is versatile; it can be used to tighten cross-head screws of both types. It should be taken into account that when screwing in a self-tapping screw with a cross type Pz, the Ph bit does not fit tightly, but with a gap. However, it is possible to tighten the Pz hardware with its help.
There are 4 standard sizes of bits, they are designated from 0 or from 1 to 4. The Ph2 bit is most often used; it is suitable for self-tapping screws with an outer diameter of 3 to 5 mm. For hardware with a smaller diameter, you need a Ph1 bit; for self-tapping screws with a diameter of 6 mm, you need a Ph3 bit. The bit must be selected according to the size of the fastener, otherwise the bit will wear out faster. In addition, when using the wrong bit, the cross on the head of the hardware breaks off, which complicates unscrewing the screw in the future.
The diameter of the drill for self-tapping screws with a press washer depends on the material into which the fasteners are to be screwed. When working with metal, the drill is selected according to the thickness of the sheet. Drills with a diameter of 3.3 and 3.4 mm are most in demand when working with self-tapping screws.
